The present invention relates to a bone regeneration material for expediting formation of a new bone tissue. More specifically, the invention relates to a bone regeneration material comprising inorganic polyphosphate.
A bone is a specialized and hardened connective tissue that is composed of cells and an extracellular matrix, and it is different from other connective tissue in that matrix of the bone is mineralized. The mineral is calcium phosphate which is a hydroxyapatite crystal (Ca10(PO4)6(OH)2). The bone is an extremely hard tissue capable of providing support and protection from physical stress. Accordingly, the reduction or the damage of the bone owing to the fracture or the pathological to change leads to the disability, the waste of time and money. When the bone is removed by any reasons, the defected bone need to be generated as soon as possible. But if regeneration of the defect cannot occur, replacement of the defect by an artificial bone or by bones from other parts of the body must be operated.
Further, in the treatment of the damage (fracture) of the bone by the physical shock or the damage of the bone accompanied by the surgical operation, the artificial middle setting of various auxiliary bones including artificial bones and immobilization or fixation of fractured portions of bones have been conducted. It takes much time until the bone restores the original shape and function, and the physical and mental stresses of patients are considerably great. Further, the longer the process to healing, the greater the opportunity in which patients might be exposed to bacterial infection. There is a fear that the damaged portions might not be healed completely. Regarding the existing selective materials for increase and regeneration of the bone, various materials which can function as artificial fillers for bone restoration, such as bioceramics, composite materials, bone morphogenetic materials, and natural and synthetic polymers have been studied.
In case of teeth, replacement and reconstruction of fractured, lost, and any pathologically or physiologically wounded bony parts in the oro-maxillofacial region are also important in many aspect. In particular, an alveolar bone supporting the teeth is vulnerable to bacterial infection. Once the alveolar bone is infected or destroyed, it can hardly be restored to the original level by itself. Generally, implantation for constructing an artificial tooth by inserting a metallic implant member in which titanium is used as a base material into a jaw bone is useful with respect to the loss of an inherent tooth. However, this implantation technique is unsatisfactory for supporting the portion of the body around the implanted part, and causes an excess occlusal force to the adjacent bony structure. Thus, this has not always been conducted successfully. As a curing method to solve these problems, there is a method for accelerating regeneration of a tissue and a bone. In order to accelerate regeneration of a bone in a defected bony area, a demineralized bone, hydroxyapatite or the other implant substitute has been used. However, no satisfactory effect has been provided.
For an ideal filler or implant material, properties such as a biocompatibility, a bactericidal activity, a bone morphogenetic activity (stimulus for phenotypically converting mesenchymal cells into osteoblasts in bone formation) and a bone conductive activity (which acts as a lattice for new bone formation) are required. Further, it is advisable that a filler is biodegradable, free from immunogenicity and non-toxic in view of the somatic tissue. However, there is actually no material that meets all of these requirements. Only a material that meets some of these requirements exists.
It is an object of the invention to provide, for overcoming the defects associated with the conventional bone curing means or substitute bone materials, a bone regeneration material which can expedite new bone formation and shorten a time that lapses until the healing or the restoration.
That is, the invention relates to a bone regeneration material for expediting formation of a new bone tissue, the bone regeneration material containing a linear condensed polyphosphoric acid or/and a polyphosphate. Further, the invention relates to a bone regeneration material for expediting regeneration of a fractured bone wherein a polyphosphate is contained in a substrate composed of a material having a biocompatibility.
Still further, the invention relates to a bone regeneration material for expediting formation of a new bone tissue wherein a polyphosphoric acid is contained in a filler for cosmetic surgery.
Furthermore, the invention relates to a bone regeneration material wherein a polyphosphoric acid is mixed with a bone morphogenetic protein or/and a natural substance containing a bone morphogenetic factor.